The present invention is related generally to wireless telecommunications, and more particularly to supporting wireless number portability (WNP). When a customer is initially assigned a wireless phone number by an original service provider, the number is assigned from a block of numbers associated with the service provider and the customer's geographical location. When the customer moves to a new service provider, the customer's phone number is ‘ported’ to the new service provider. Number portability allows a user to change service providers for mobile communications while keeping their mobile directory number (MDN), and is therefore popular among wireless service customers. Wireless number portability standards have been established by various industry bodies, including the Cellular Telecommunications Industry Association (CTIA), in which a wireless number portability (NP) database is maintained with entries of ported mobile directory numbers and corresponding location routing numbers (LRNs) for access by switching components operated by various wireless service providers. The home or anchor switch in the original service provider's network maintains a local ported number database or table with entries corresponding to 1000 number blocks that include at least one number that has been ported to another service provider. When a call is placed to a ported wireless number, the originating switch receives the call and queries the local ported number database to determine whether the called number is portable (possibly ported). If the called number is within a 1000 number block identified in the local ported number database, the switch sends a WNP query invoke message through the network to the common number portability (NP) database at a number portability service control point (NP-SCP). If this NP database includes an entry for the called number, the corresponding LRN is returned to the originating switch, which then routes the call to the receipt switch associated with the LRN, along with one or more parameters indicating that the call is to a ported number. This WNP service standard therefore requires construction and maintenance of the NP-SCP on the network, which is an extra cost to the service provider. Moreover, the queries to the NP database take time and occupy system resources to determine whether a portable number is indeed ported. Thus, there is a need for improved systems and methods for supporting WNP services in a wireless network without maintaining a common number portability database and without requiring the originating switch to perform excessive network queries to determine whether a called number is ported.